1. Technical Field
The present invention relates to an array substrate for a liquid crystal panel, to a liquid crystal panel, and to manufacturing methods thereof, and, in particular, to realizing an increase in an area of a capacitor and inhibition of an enlargement of the peripheral region in a structure of an array substrate having two display electrodes forming an electric field for controlling an alignment of liquid crystal and a capacitor provided in the peripheral region (also called a “frame region”).
2. Related Art
In liquid crystal panels using a low temperature polysilicon (LTPS), it is very common for a part of a driving device such as, for example, a shift register, a voltage boosting circuit, a buffer, and so on to be formed in a peripheral region of an array substrate. In addition, in a liquid crystal panel in which circuits such as a digital-to-analog converter (DAC) are built in the peripheral region, a capacitance element, that is, a capacitor, which is necessary for the circuit is formed by a layered structure of a gate line and a polysilicon line or a layered structure of a gate line and a source line. The capacitor is placed alongside the circuit elements.
In recent years, there has been active effort to develop FFS (Fringe Field Switching) mode liquid crystal panels having a wide angle of view, such as those disclosed in, for example, JP-A-2002-296611.
In low temperature polysilicon techniques, the formation of a thin insulating film suitable for a capacitor is not necessarily easy, and, in general, the capacitor insulating film is formed in a thick thickness. Thus, the capacitor electrode is widened to increase the capacitance.
However, increasing the area occupied by the capacitor creates a disadvantage in that the peripheral region in which the capacitor is placed must be enlarged.